An excellent paper authored by Dr. Jeremy Arden about the "Schillinger System of Musical Composition" as a submission for his degree of PhD in music. SSoMC is a mathmatically based approach to writing music. It served as the core principles on which the Berklee School of Music was founded.
Dr. Jeremy Ardern's thesis (pdf)
Many thanks to Dr. Arden for giving me permission to host his work and share with everybody!